创建用户

create user 'clown'@'%' identified by mysql_native_password '123456';

授权

grant all privileges on nacos.* to 'clown'@'%' with grant option;
grant select,create,delete,update on nacos.* to 'clown'@'%' with grant option;

收回权限

revoke select,create,delete,grant option on nacos.*  from 'clown'@'%';
revoke all privileges,grant option from 'clown'@'%';
-- 或者
revoke all privileges on nacos.* from 'clown'@'%';
revoke grant option on nacos.* from 'clown'@'%';

授予什么权限就回收什么权限

grant select on *.* to 'clown'@'%' with grant option;

授予全局权限,权限信息保存在mysql.user表中

select * from mysql.user where user='clown'\G;
*************************** 1. row ***************************
                  Host: %
                  User: clown
              Password: *06C0BF5B64ECE2F648B5F048A71903906BA08E5C
           Select_priv: Y
           Insert_priv: N
           Update_priv: N
           Delete_priv: N
           Create_priv: N
             Drop_priv: N
           Reload_priv: N
         Shutdown_priv: N
          Process_priv: N
             File_priv: N
            Grant_priv: Y
       References_priv: N
            Index_priv: N
            Alter_priv: N
          Show_db_priv: N
            Super_priv: N
 Create_tmp_table_priv: N
      Lock_tables_priv: N
          Execute_priv: N
       Repl_slave_priv: N
      Repl_client_priv: N
      Create_view_priv: N
        Show_view_priv: N
   Create_routine_priv: N
    Alter_routine_priv: N
      Create_user_priv: N
            Event_priv: N
          Trigger_priv: N
Create_tablespace_priv: N
              ssl_type: 
            ssl_cipher: 
           x509_issuer: 
          x509_subject: 
         max_questions: 0
           max_updates: 0
       max_connections: 0
  max_user_connections: 0
                plugin: mysql_native_password
 authentication_string: 
      password_expired: N

grant select on nacos.* to 'clown'@'%' with grant option;

授予数据库权限，权限信息保存在mysql.db表中

select * from mysql.db\G;
*************************** 1. row ***************************
                 Host: %
                   Db: nacos
                 User: clown
          Select_priv: Y
          Insert_priv: N
          Update_priv: N
          Delete_priv: N
          Create_priv: N
            Drop_priv: N
           Grant_priv: Y
      References_priv: N
           Index_priv: N
           Alter_priv: N
Create_tmp_table_priv: N
     Lock_tables_priv: N
     Create_view_priv: N
       Show_view_priv: N
  Create_routine_priv: N
   Alter_routine_priv: N
         Execute_priv: N
           Event_priv: N
         Trigger_priv: N

grant select on nacos.user to 'clown'@'%' with grant option;

授予某张表权限，权限信息保存在mysql.tables_priv表中

select * from mysql.tables_priv;
+-----------+-----+-------+------------+----------------+---------------------+--------------+-------------+
| Host      | Db  | User  | Table_name | Grantor        | Timestamp           | Table_priv   | Column_priv |
+-----------+-----+-------+------------+----------------+---------------------+--------------+-------------+
| %         |nacos| clown | user       | root@localhost | 0000-00-00 00:00:00 | Select,Grant |             |
+-----------+-----+-------+------------+----------------+---------------------+--------------+-------------+

grant select(name) on nacos.user to 'clown'@'%' with grant option;

授予某个字段的权限，权限信息保存在mysql.columns_priv表中

select * from mysql.columns_priv;
+-----------+-----+-------+------------+-------------+---------------------+-------------+
| Host      | Db  | User  | Table_name | Column_name | Timestamp           | Column_priv |
+-----------+-----+-------+------------+-------------+---------------------+-------------+
| %         |nacos| clown | user       | name        | 0000-00-00 00:00:00 | Select      |
+-----------+-----+-------+------------+-------------+---------------------+-------------+

当使用

revoke all privileges on *.* from 'clown'@'%';

回收的只是全局的权限，clown用户其他的权限，比如对nacos数据库的权限，对user表的权限，对某个字段的权限仍然持有。所以为了回收用户的所有权限，使用

revoke all privileges,grant option from 'clown'@'%';

这是条固定语法，all privileges和grant option必须都有

MySQL 回收用户权限

创建用户

授权

收回权限

授予什么权限就回收什么权限